A randomized controlled trial published in Sleep Medicine in 2024 found that taking 1 gram (g) of magnesium L-threonate per day for 3 weeks helped improve sleep in study participants.
The researchers conducted this intervention in adults ages 35 to 55 years who reported sleep problems. There were 80 participants in total, and the researchers controlled for effectiveness by comparison with a placebo.
Another randomized, placebo-controlled trial, published in Nature and Science of Sleep in 2025, found that a different type of magnesium supplement, magnesium bisglycinate, produced modest improvements in adults with insomnia.
This trial totaled 155 participants ages 18 to 65 years with sleep problems. About half of these took 250 milligrams (mg) of magnesium bisglycinate per day over 4 weeks. The rest took a placebo.
A review of several trials — published in Cureus in 2024 — looking at the effect of different forms of magnesium on sleep quality and anxiety found the evidence to be too mixed to draw a sufficiently strong conclusion about whether or not magnesium supplementation can really help improve sleep.
“[T]he evidence for magnesium as a general sleep aid is still relatively limited,” Ünlüişler told MNT.
